Effect of inlet particle arrangement on separating property of a cyclone separator

An-Lin Liu,Yan-Hong Zhang,Liang Ma,Yi-Mou Wang,Meng-Ya He 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.6

Different arrangements of particles on the inlet section exert different effects on the separation property of a cyclone separator. Sorting classifier with different heights was connected in series with a conventional cyclone, positive rotation cyclone, and reverse rotation cyclone respectively, to investigate the effect of particle arrangement on the separation property and inner flow field. Results indicate that the implementation of a sorting classifier increases the pressure drop and energy consumption of a cyclone separator. The taller the sorting classifier, the larger the flow is. The energy consumption in positive rotation cyclone is closer to that in reverse rotation cyclone. Meanwhile, the tangential velocity in inner flow field is higher and the separating property is enhanced. The reverse rotation cyclone relieves the fishhook effect, whereas the positive rotation cyclone eliminates such effect. The reverse and positive rotation cyclones demonstrate an improved separating property for particles smaller and greater than 1 m, respectively. Moreover, the reverse rotation cyclone demonstrates superior overall separation, but the positive rotation cyclone demonstrates a greater classification effect than the reverse rotation cyclone.

Evaluation of fine particle removal capability of multi inner stage cyclone

이상준,김동빈,채승기,정경환,이원영,박문수,김형우,김태성 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6

A three-layer-type multi inner stage (MIS) cyclone capable of removing fine particles generated by electronic industrial processes was successfully developed with a high processing rate, minimal maintenance and repair cost, and low energy loss. To investigate the capability of the MIS cyclone, experiments were performed using Al 2 O 3 particles with diameters of 1, 3, 5, 10, 15 and 20 μm under particle inlet velocities of 0.85, 2.55, 4.25, 5.94 and 8.49 m/s. Lapple (1950), Barth (1956), and Iozia and Leith (1989) prepared a cyclone efficiency prediction graph using a collection efficiency prediction model under the same operating conditions as the MIS cyclone. They verified the cyclone efficiency by comparing the efficiency prediction graph and the general cyclone experimental data with the MIS cyclone experimental data. For an Al 2 O 3 fine particle diameter smaller than 5 μm, the particle removal capability of the MIS cyclone was observed to be significantly higher than that of the predicted efficiency of a general cyclone and its actual experimental efficiency. Furthermore, the variation of collection efficiency with particle size was not as significant as that of a general cyclone, which suggested the MIS cyclone possesses a more stable removal capability. Pressure drop measurement results of the MIS cyclone showed that a maximum pressure drop of 11 mmAq occurred under an inlet velocity of 8.49 m/s, which was considerably lower than that of a general cyclone pressure drop (50~150 mmAq).

연속적인 곡선으로 정의 되는 볼록한 형상의 사이클론에 대한 연구

허광수(Heo Kwang-Su),설승윤(Seol Seoung-Yun),리진철(Li Zhen-Zhe) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

A cyclone design concept named Convex cyclone was developed to reduce pressure losses. Contrary to conventional cylinder-on-con type cyclone, inner wall of Convex cyclone are defined with a continuous curve and it has convex shape body. The discontinuity of inner diameter variation rate of cylinder-on-con type cyclone cause additional pressure loss. Continuous wall of Convex cyclone prevent additional pressure loss. In order to verify Convex cyclone design concept, we make a comparative experiments between Stairmand HE and Convex cyclone. Experimental Convex cyclone designed based on Stairmand HE model, and inner wall are defined with circular arch. The experimental result clearly shows that Convex cyclone can achieve maximum 50% pressure loss reduction with a few percent of collection efficiency drop. In addition, the experimental results indicated the existence of optimum convexity, minimum pressure loss, of cyclone wall.

Multi-objective optimization of a Stairmand cyclone separator using response surface methodology and computational fluid dynamics

Sun, Xun,Kim, Sung,Yang, Seung Deok,Kim, Hyun Soo,Yoon, Joon Yong Elsevier Sequoia 2017 Powder technology Vol.320 No.-

<P><B>Abstract</B></P> <P>The performance of a cyclone is generally assessed using the pressure drop and the collection efficiency of the cyclone. In the present paper, a multi-objective optimization of a classic Stairmand cyclone separator is executed using the response surface methodology (RSM), combined with computational fluid dynamics (CFD) techniques for minimizing the pressure drop and maximizing the collection efficiency. Ten cyclone geometrical factors are considered in this work. Three of them are studied using the RSM according to the results of the preceding screening experiments. The second-order response surface models for each response are successfully carried out using the central composite design (CCD) in the RSM. The desirability function approach is used to optimize the geometrical factors of the cyclone. In comparison to the reference model, the optimal cyclone model decreases the pressure drop by 20.70% and the cut-off size by 75.38%. The accuracies of the response surface models are confirmed and the correctness of the optimal cyclone model is also validated using CFD; the results indicate excellent performance and reliability of the response surface model and the RSM optimization result. According to the analyses of the obtained flow fields, there are several reasons why decreases in the cut-off size with a lower pressure drop are found in the optimal model. The primary reasons for improvements are optimized values of relevant geometrical factors, the production of a distinct, undisturbed downward flow, an increase in the tangential velocity at the near wall region, and a decrease in the peak tangential velocity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A multi-objective optimization of a Stairmand cyclone is executed. </LI> <LI> Nine geometrical factors and two objective functions are considered. </LI> <LI> Response surface methodology and computational fluid dynamics are utilized. </LI> <LI> The reasons leading to improve the performance are explained in detail. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A study on the optimal design of a cyclone system for vacuum cleaner with the consideration of house dust

하건호,김응달,김영수,이재근,안영철,김동규 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.3

Cyclone, a type of particle collector widely used in the field of ambient sampling and industrial particulate control, is the principal type of gas-solids separator that use a centrifugal force. The goal of this study is to transform conventional cyclone into a new type of cyclone that can be used for the household vacuum cleaners. To meet the goal, first, the analysis about local environment and dust is carried out. Second, it must have enough high-efficiency not to reduce suction power due to clogging of exhaust filter unit. Two single cyclones with central-hopper-dust-outlet and side-wall-dust-outlet and a twin cyclone are designed and fabricated to evaluate, and compare, their dust collection efficiencies and pressure drops. The measurements of separation efficiency for dust by using DMT test dust type 08 are carried out. House dust experiment is additionally performed to check the local matters applicability such as tissue papers, fur and hairs. The collection efficiency of the twin cyclone is found to be 3-6% greater than those of two single cyclones with the same body diameter, inlet and inner cylinder diameter. Twin cyclone with a large body diameter, a small inner cylinder diameter, a short inner cylinder, a narrow inlet has high separation efficiency. This result indicates the possibility of achieving higher collection efficiencies with a twin cyclone.

Experimental study of biomass combustion and separation using vertical cyclone combustor

Ahmed Gharib,Ibrahim Abdel-Rahman,Mohamed Shehata 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.11

The present work is devoted to study experimentally the effect of the vortex finder length to the cyclone height ratio (S/H), the air flow rate, and the biomass particles (diameters, feeding flow rates, and type) on the separation efficiency of the cyclone in cold tests. Results from the cold tests were taken as a base of the combustion tests in order to identify the optimum operating conditions. In addition, the combustion characteristics of the cyclone were studied. The experimental results showed that, by increasing the air flow rate, the biomass particles diameter and decreasing the biomass feeding flow rate, the separation efficiency increased. Also, by increasing the vortex finder length to the cyclone height ratio (S/H) the separation efficiency increased for vortex finder ratios greater than 8 % up to 16 % where the separation efficiency reached its maximum value. After that, the separation efficiency started to decrease by further increase of the vortex finder ratio. It is worth stating that, the fine biomass particles gave lower separation efficiency than the coarse particles at whole ranges of feeding flow rates. For all particles diameters, the maximum centerline axial temperatures were obtained at the top of the cyclone. For coarse particles diameters, the centerline axial temperature started to decrease until axial distance of y/D = 3. After that, the centerline axial temperature increased slightly until the exit of the cyclone. For fine particles diameters the centerline axial temperature decreased until the bottom of the cyclone. Finally, the combustion of LPG and biomass fuel mixture revealed higher values of radial temperatures than those obtained from the combustion of the LPG only at the same thermal load.

Guide-Vane의 형태에 따른 멀티 사이클론의 압력손실 변화

박형용(Hyeong-Yong Park),조성광(Sung-Kwang Cho),설승윤(Seoung-Yun Seol) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Cyclone is the one of the dust-separating mechanism that using centrifugal force. Performance of the cyclone is indicated by pressure loss and collection efficiency. Sometimes, Multi-cyclone is used to improve the collection efficiency in limited area. In this case, install the guide-vane in the 1st cyclone’s vortex finder in order to reduce the additional pressure loss. In this study, we have found that the shape of guide vane can affect the reduction effect of multi cyclone’s pressure loss. And this effect can be varied by the diameter and length of vortex finder and the flow direction between 1st cyclone and 2nd cyclones.

등급집진효율 곡선의 기울기가 2단 사이클론의 집진효율에 미치는 영향

허광수(Heo Kwang Su),설승윤(Seol Seoung-Yun),김민하(Kim Min Ha) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

A collection efficiency of cyclone is influenced by cut-size and slope of grade efficiency curve. It has been recognized that the collection efficiency is improved when the cut-size is reduced. However, effects of the slope have never been studied so far. In this study, we analyze a relationship between slope of grade efficiency and collection efficiency in two-stage cyclones. In single stage cyclones, higher slope cyclones have high efficiency. On the contrary to single stage cyclone, collection efficiency of two-stage cyclone have the maximum value when the first cyclone has a lower slope and second cyclone is high.

Water - cyclone 장치의 미세입자, 기체상 오염 물질 처리 방법 연구 및 실험적 검증

권성안(Sung-An Kwon),이상준(Sang-Jun Lee) 한국산업융합학회 2014 한국산업융합학회 논문집 Vol.17 No.1

Recently, cyclone is used to collect fine particles in various industrial precesses, but many studies are undergoing because of cyclone"s low collection efficiency. Thus, we have developed water-cyclone which minimizes disadvantages of existing conventional cyclone and designed 3 different stages depending on precessing materials. Stage 1 collects particles by using principles of conventional cyclone. Stage 2 processes acid gases by extending contact time with water film through vortex movement. Stage 3 processes uncollected substances in stage 1 and 2. Hence, we evaluate water-cyclone by experimental verification.

멀티사이클론을 이용한 진공청소기의 최적설계에 관한 연구

하건호(Gun-Ho Ha),김응달(Eung-dal Kim),양병선(Byung-Sun Yang),안영철(Young-Chull Ahn) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.2

Cyclone, a type of particle collector widely used in the field of ambient sampling and industrial particulate control, is the principal type of gas-solids separator that uses a centrifugal force. The goal of this study is to design and evaluate the cyclone that can be used for the household vacuum cleaners. A multi cyclone with a 1st cyclone and several 2nd cyclones is designed to improve dust collection efficiency. The dust collection efficiency and the suction power of 1st cyclone are evaluated. And the dust collection efficiency and the suction power of multi cyclone are evaluated according to various sizes of inlet and vortex finder. As a result, a cone shape porous filter has better dust collection efficiency than a cylinder shape porous filter. The dust collection efficiency of a multi cyclone is 3.5% greater than that of a single cyclone.